Connecticut Reports West Nile Virus Positive Mosquitoes

Ruzanna Harutyunyan's picture

The State Mosquito Management Program announced that mosquitoes trapped in Milford and in Monroe on August 17, 2009 have tested positive for West Nile virus (WNV). These are the first positive mosquitoes identified in Milford and in Monroe by the Connecticut Agricultural Experiment Station (CAES) this year.

“The continued isolation of West Nile virus in mosquitoes is expected at this time of the season and can be expected to increase over the next two months,” said Theodore G. Andreadis, Ph.D., Chief Medical Entomologist, CAES. “We will continue to monitor and report on mosquito populations through October.”


In 2009, WNV-positive mosquitoes have been trapped in seven towns including: Darien, Cromwell, Greenwich, Milford, Monroe, Old Lyme and Stratford. Killingworth is the only town where EEE-positive mosquitoes have been trapped. No Connecticut residents have been identified with WNV or EEE infections.

“The risk of mosquito-transmitted diseases like West Nile virus and eastern equine encephalitis virus usually increases through the late summer and early fall,” said Department of Public Health (DPH) Commissioner, J. Robert Galvin, M.D., M.P.H., M.B.A. “I am urging Connecticut residents to take announcements seriously and to take precautions to prevent mosquito bites.”

Monitoring and risk assessment for WNV emphasizes mosquito trapping and testing results. The CAES maintains a network of 91 mosquito-trapping stations in 72 municipalities throughout the state. Mosquito traps are set Monday – Thursday nights and conducted at each site every ten days on a rotating basis. Mosquitoes are grouped (pooled) for testing according to species, collection site, and date.

Each pool is tested for the presence of viruses of public health importance. Positive findings are reported to local health departments, in press releases and on the CAES web site.